scholarly journals Continuous multi-step synthesis by extrusion – telescoping solvent-free reactions for greater efficiency

2017 ◽  
Vol 53 (97) ◽  
pp. 13067-13070 ◽  
Author(s):  
Deborah E. Crawford ◽  
Clodagh K. Miskimmin ◽  
John Cahir ◽  
S. L. James
Keyword(s):  
Continuous Process ◽  
Solvent Free ◽  
Twin Screw Extrusion ◽  
Screw Extrusion ◽  
Twin Screw

Herein, we demonstrate that several reactions can be telescoped into a single continuous process and/or be carried out as a continuous multi-component reaction (MCR), by twin screw extrusion (TSE), in the complete absence of solvent.

scholarly journals Solvent-Free, Continuous Synthesis of Hydrazone-Based Active Pharmaceutical Ingredients by Twin-Screw Extrusion

2020 ◽  
Vol 8 (32) ◽  
pp. 12230-12238 ◽  
Author(s):  
Deborah E. Crawford ◽  
Andrea Porcheddu ◽  
Aaron S. McCalmont ◽  
Francesco Delogu ◽  
Stuart L. James ◽  
...  
Keyword(s):  
Solvent Free ◽  
Active Pharmaceutical Ingredients ◽  
Twin Screw Extrusion ◽  
Pharmaceutical Ingredients ◽  
Continuous Synthesis ◽  
Screw Extrusion ◽  
Twin Screw

scholarly journals Organic synthesis by Twin Screw Extrusion (TSE): continuous, scalable and solvent-free

2017 ◽  
Vol 19 (6) ◽  
pp. 1507-1518 ◽  
Author(s):  
Deborah E. Crawford ◽  
Clodagh K. G. Miskimmin ◽  
Ahmad B. Albadarin ◽  
Gavin Walker ◽  
Stuart L. James
Keyword(s):  
Organic Synthesis ◽  
Solvent Free ◽  
Pure Form ◽  
Organic Reactions ◽  
Twin Screw Extrusion ◽  
Continuous Basis ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Work Up

Several organic reactions have been achieved quantitatively without any added solvent, using solid or liquid reagents, on a continuous basis; products are typically obtained directly in analytically pure form, requiring no work-up.

scholarly journals Greener Dye Synthesis: Continuous, Solvent‐Free Synthesis of Commodity Perylene Diimides by Twin‐Screw Extrusion

2020 ◽  
Vol 132 (11) ◽  
pp. 4508-4513
Author(s):  
Qun Cao ◽  
Deborah E. Crawford ◽  
Chengcheng Shi ◽  
Stuart L. James
Keyword(s):  
Solvent Free ◽  
Twin Screw Extrusion ◽  
Perylene Diimides ◽  
Screw Extrusion ◽  
Twin Screw ◽  
Solvent Free Synthesis

scholarly journals In-Line Rheo-Optical Investigation of the Dispersion of Organoclay in a Polymer Matrix during Twin-Screw Compounding

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2128
Author(s):  
Paulo F. Teixeira ◽  
José A. Covas ◽  
Loïc Hilliou
Keyword(s):  
Local Heating ◽  
Polymer Nanocomposite ◽  
Structural Rearrangement ◽  
Particle Dispersion ◽  
Optical Investigation ◽  
Twin Screw Extrusion ◽  
Clay Particles ◽  
Clay Dispersion ◽  
Screw Extrusion ◽  
Twin Screw

The dispersion mechanisms in a clay-based polymer nanocomposite (CPNC) during twin-screw extrusion are studied by in-situ rheo-optical techniques, which relate the CPNC morphology with its viscosity. This methodology avoids the problems associated with post extrusion structural rearrangement. The polydimethylsiloxane (PDMS) matrix, which can be processed at ambient and low temperatures, is used to bypass any issues associated with thermal degradation. Local heating in the first part of the extruder allows testing of the usefulness of low matrix viscosity to enhance polymer intercalation before applying larger stresses for clay dispersion. The comparison of clay particle sizes measured in line with models for the kinetics of particle dispersion indicates that larger screw speeds promote the break-up of clay particles, whereas smaller screw speeds favor the erosion of the clay tactoids. Thus, different levels of clay dispersion are generated, which do not simply relate to a progressively better PDMS intercalation and higher clay exfoliation as screw speed is increased. Reducing the PDMS viscosity in the first mixing zone of the screw facilitates dispersion at lower screw speeds, but a complex interplay between stresses and residence times at larger screw speeds is observed. More importantly, the results underline that the use of larger stresses is inefficient per se in dispersing clay if sufficient time is not given for PDMS to intercalate the clay galleries and thus facilitate tactoid disruption or erosion.

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